Odor prevention in connection with the use of absorbent products, such as incontinence products, is an important comfort factor for consumers. Bodily fluid, such as urine, is collected and stored in absorbent products and odors may easily arise. It is important for the wearer that these odors do not spread into the environment. The wearer needs to feel safe when using absorbent products both in respect of leakage and odor prevention or control.
In the field of absorbent products, several different solutions are used to prevent odors. For example, odors can be masked by the use of perfumes or deodorizing compounds. Odors may also be adsorbed or absorbed to particles having a large surface area, such as activated carbon, zeolite and starch-based particulate materials. Acidic and/or alkaline odors may be neutralized by the use of substances like baking soda and/or citric acid. For bacteria inhibition, substances having low pH or metal salts can be used. Accordingly, different odor control agents may be used to prevent odors in different manners.
Odor control agents in particle form, such as activated carbon, zeolite and starch-based materials, have been proved to have excellent odor-adsorbing characteristics due to the large surface area of the particles. However, there are some drawbacks related to the use of such odor control agents which may be in a powder form, for example, such powders are very difficult to handle in dry processes due to dusting problems. Powders may contaminate both process equipment and products.
In the prior art, there have been attempts to decrease dusting problems of powders as for example disclosed by EP0392528, in which particles of odor control agent is bond to a fibrous base web, such as non-woven or paper web. The porous base web is dipped in a saturated slurry containing the odor-absorbing particles and a binding agent, together with a surfactant. The excess slurry is then squeezed from the web and the web is dried.
Odor control agent in particle form may also be difficult to disperse in an even manner in the absorbent products. For example, humidity of the atmosphere may cause the particles to build lumps, and this may cause an uneven distribution in the production process and consequently in final products.
Since certain odor adsorbing particles such as for example activated carbon particles are hydrophobic it is also important that these particles do not impair the absorption properties in the product.
Thus, there is still a need to improve the handling of odor control agents in particle form during the production of absorbent products and also a need to secure that the odor adsorbing/absorbing properties as well as the liquid absorption properties are maintained or improved.